"ST151" 100W amplifier

[shreya]

can i use 2n3773 transistors in the out put stage i.e Q8,Q9,Q12,Q13 by giving +/-50v

 

[xeclipse]

More Pictures. this one is a closeup view of the build.

no one's pointing this out: you got fake output transistors!

 

[john g]

hi macd, have you finished this amp i'm also SA where did u get toroidal tx my email is ejhgbb@gmail.com im busy locating parts to do this amp and wondering maybe u can help txs john

 

[john g]

hi sixtek,
cannot download file as it is damaged can u repair please. need new pcb pdf (file).
http://sixtek.uw.hu/st151_nyak.pdf
txs john

 

[diy didi]

Ok so i've built this amp. It works for about 30min at loud volume then outputs blow I'm using a 4ohm speaker. My supply is -/+ 48V.
I've used tip35/36, 2sc5200/2sa1943 and also mjl21194/95.
Is my heatsink too small?? Will a larger heatsink change SOA of devices for the better?

 

[AndrewT]

+-48Vdc should get you close to 200W into 4r0.
For BJTs I suggest you use ~5 to 6times that target power for the total device power, i.e ~1100W of device power. For 1943/5200 @ 150W each, that comes to either 3pairs or 4pairs.

I suspect it's not just a heatsink inadequacy problem!

 

[homemodder]

If youre using bd139 and bd140 as drivers, those will fail before the outputs, outputs will follow soon afterward.

 

[Jay]

Nice sound amplifier design you have here. It is a classic topology (called LIN)that has many flavors.

I'm sorry

 

[john g]

Hi didi cant u post a pic of ur set up cause vi got a lottya help from homemodder and im busy boxing my ST1

 

[rana]

helllo i'm here please help me stk4141
i don't know how make vloume bass treble sound control
please give me volume line out
thank u

An externally hosted image should be here but it was not working when we last tested it.

​

 

[john g]

ST1 AMP

there is something wrong with DIY i cant post pics it goes to post URL'S

 

[john g]

ST1 AMP

Hi guys sorry dec jan been too long working

 

[john g]

So far it is working geat

 

[diy didi]

John G! Nice box!!
Where did you get it?

 

[stoN_Cold]

Hi guys sorry dec jan been too long working

Nice fingers

 

[astankov]

Nice fingers

 

[homemodder]

John G! Nice box!!
Where did you get it?

In the olden days I used to buy enclosures from Apon electronics, they werent too expensive. Give them a call, very friendly japanese staff. Special of the Week - Toptronic (PTY) Ltd T/A AP ELECTRONICS

 

[Hadighorbani]

Hi guys
how can i use this amp in real 2 ohm stable?
it must be 100w rms on 2 ohm impedance
how many volts?
thanks

 

[AndrewT]

Vpk = sqrt(P*Rload*2) = sqrt(100*2*2) = 20Vpk.
PSU ~+-25Vdc for 100W into 2ohms speaker. Expect peak transient current to approach ~30A.

 

[Hadighorbani]

Vpk = sqrt(P*Rload*2) = sqrt(100*2*2) = 20Vpk.
PSU ~+-25Vdc for 100W into 2ohms speaker. Expect peak transient current to approach ~30A.

Thank you dear friend
+-32vdc=???w 2ohm